It can be done, quitting together, but each person has to have their own plan. As was mentioned above, comparisons and competition are detrimental. To me, at least. I have 16 months. My husband relapsed before Christmas. It's been really hard to stay focused on me but I have to. What has been working for me won't work for him and vvice versa. But I get caught in the trap of "I'm doing it? Why aren't you? You know how to do it!!!" Because he does. He's had longer periods of sobriety than I. The risk of one of you relapsing also is a trigger. I've had to work extra hard not to drink at my husband and my anger.
But you can be very supportive of each other. Personally, I don't like attending AA meetings with my husband. I go, but on my own. I always feel that when he shares something he's merely blowing smoke for my benefit and not because he's serious.
Good luck!